perf: clear vfs audit_cache before each run
When generating a stream clone, we spend a large amount of time auditing path.
Before this changes, the first run was warming the vfs cache for the other
runs, leading to a large runtime difference and a "faulty" reported timing for
the operation.
We now clear this important cache between run to get a more realistic timing.
Below are some example of median time change when clearing these cases. The
maximum time for a run did not changed significantly.
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# benchmark.name = hg.perf.exchange.stream.generate
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.version = latest
no-clearing: 17.289905
cache-clearing: 21.587965 (+24.86%, +4.30)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
no-clearing: 32.670748
cache-clearing: 40.467095 (+23.86%, +7.80)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
no-clearing: 37.838858
cache-clearing: 46.072749 (+21.76%, +8.23)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
no-clearing: 32.969395
cache-clearing: 39.646209 (+20.25%, +6.68)
In addition, this significantly reduce the timing difference between the
performance command, from the perf extensions and a `real `hg bundle` call
producing a stream bundle. Some significant differences remain especially on
the "mozilla-try" repositories, but they are now smaller.
Note that some of that difference will actually not be
attributable to the stream generation (like maybe phases or branch map
computation).
Below are some benchmarks done on a currently draft changeset fixing some
unrelated slowness in `hg bundle` (34a78972af409d1ff37c29e60f6ca811ad1a457d)
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
hg.perf.exchange.stream.generate: 21.587965
hg.command.bundle: 24.301799 (+12.57%, +2.71)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 40.467095
hg.command.bundle: 44.831317 (+10.78%, +4.36)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 39.646209
hg.command.bundle: 45.395258 (+14.50%, +5.75)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 46.072749
hg.command.bundle: 55.882608 (+21.29%, +9.81)
## data-env-vars.name = mozilla-try-2023-03-22-zlib-general-delta
hg.perf.exchange.stream.generate: 334.716708
hg.command.bundle: 377.856767 (+12.89%, +43.14)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 302.972301
hg.command.bundle: 326.098755 (+7.63%, +23.13)
$ hg init t
$ cd t
$ echo a > a
$ hg add a
$ hg commit -m test
$ rm .hg/requires
$ hg tip
abort: unknown version (65535) in revlog 00changelog
[50]
$ echo indoor-pool > .hg/requires
$ hg tip
abort: repository requires features unknown to this Mercurial: indoor-pool
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ echo outdoor-pool >> .hg/requires
$ hg tip
abort: repository requires features unknown to this Mercurial: indoor-pool outdoor-pool
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ cd ..
Test checking between features supported locally and ones required in
another repository of push/pull/clone on localhost:
$ mkdir supported-locally
$ cd supported-locally
$ hg init supported
$ echo a > supported/a
$ hg -R supported commit -Am '#0 at supported'
adding a
$ echo 'featuresetup-test' >> supported/.hg/requires
$ cat > $TESTTMP/supported-locally/supportlocally.py <<EOF
> from mercurial import extensions, localrepo
> def featuresetup(ui, supported):
> for name, module in extensions.extensions(ui):
> if __name__ == module.__name__:
> # support specific feature locally
> supported |= {b'featuresetup-test'}
> return
> def uisetup(ui):
> localrepo.featuresetupfuncs.add(featuresetup)
> EOF
$ cat > supported/.hg/hgrc <<EOF
> [extensions]
> # enable extension locally
> supportlocally = $TESTTMP/supported-locally/supportlocally.py
> EOF
$ hg -R supported debugrequirements
dotencode
dirstate-v2 (dirstate-v2 !)
featuresetup-test
fncache
generaldelta
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
$ hg -R supported status
$ hg init push-dst
$ hg -R supported push push-dst
pushing to push-dst
abort: required features are not supported in the destination: featuresetup-test
[255]
$ hg init pull-src
$ hg -R pull-src pull supported
pulling from supported
abort: required features are not supported in the destination: featuresetup-test
[255]
$ hg clone supported clone-dst
abort: repository requires features unknown to this Mercurial: featuresetup-test
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ hg clone --pull supported clone-dst
abort: required features are not supported in the destination: featuresetup-test
[255]
Bundlerepo also enforces the underlying repo requirements
$ hg --cwd supported bundle --all ../bundle.hg
1 changesets found
$ echo outdoor-pool > push-dst/.hg/requires
$ hg --cwd push-dst log -R ../bundle.hg -T phases
abort: repository requires features unknown to this Mercurial: outdoor-pool
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ cd ..